Load bearing textile clamp

ABSTRACT

An invention where a removable load bearing textile clamp comprised of an outer compressive sleeve configured to accept an internally positioned removable rod such that a textile can be led around the rod and positioned inside the compressive sleeve and said sleeve once fastened can form a clamp assembly between the sleeve, rod, and textile to create a load bearing textile clamp that can be attached to a secondary structure such that the fiber strength of the textile is retained and the textile panel can perform work.

FIELD OF THE INVENTION

This invention relates to methods of reinforcing and attaching the edges of a textile panel such that they are able to convey loads into a secondary structure such that the load is resisted, energy is transferred, and the panel does work. Primarily, load bearing articles made of textiles are designed to work in tension, where the strength and orientation of fibers is a determining factor in how the article is used and the methods used to transition loads into a secondary structure is a determining factor in the load bearing capacity of the device. Articles such as lifting devices, tension structures and protective barriers such as blast screens and hurricane shutters are examples of products where the tensile strength and lightweight properties of modern textiles have been used to create new products.

BACKGROUND OF THE INVENTION

For millennia, man has used woven textile goods for a variety of domestic and industrial applications. To enable woven materials to be put to use, techniques were developed to reinforce the edges such that the textile could be attached to a secondary structure to do work. As an example, seafarers from antiquity developed the durable techniques of sewing attachment straps and using grommets on those reinforced edges that allowed cloth panels to be affixed to a secondary structure such as a mast and connected to a pole or control rope to drive a vessel through the water by the force of wind. Two principle factors limited the ability of a sail to transfer the potential wind energy into a force to drive a vessel: the first being the strength of the cloth; the second being the method used to reinforce the edge and affix the sailcloth to the support structure. While today these traditional techniques are widespread, it was over much of the course of known history that these methods were developed.

The range of applications for industrial textiles up to the development of modern synthetic materials was self limiting. Natural fibers could be made no stronger than their natural state. The techniques based on principles of sewing hems to reinforce the edge and attaching grommets or straps to fasten the textiles made from these fibers were largely sufficient, as the strength of these methods of reinforcement and attachment often exceeded the strength of the fibers in the panel itself. The only way to make a stronger textile panel was to increase the quantity of fibers in the textile. Textiles of natural fibers quickly became impractical for many high load applications which naturally limited the development of additional uses and methods of attachment. The rise of modern synthetic fibers yielded textiles that are far stronger than textiles of natural fibers and have resulted in a vast number of new and innovative products.

Current art describes a range of textile devices intended for high load applications which use some form of the traditional methods to reinforce and attach the edges. U.S. Pat. No. 6,176,050 issued to Gower and U.S. Pat. No. 6,959,748 issued to Hudoba show examples of textiles used as a hurricane barriers. Gower uses straps sewn onto a hemmed and stitched edge, while Hudoba uses grommets on an edge reinforced by welding a second strip of material. Similar to Gower, U.S. Pat. No. 4,781,473 issued to LaFleur shows straps for lifting sewn onto a large flexible material bulk container whose edges have been reinforced with layered and stitched hems. Similar to Hudoba, U.S. Pat. No. 5,529,321 issued to Thompson shows a hauling harness for a load carrying tarp which has double layer reinforced edges with grommets. U.S. Pat. No. 7,216,908 issued to Daigle, shows a textile lift bag used to loaded and unload bulk materials more easily; its edges are hemmed and reinforced with sewn on webbing to which lift straps are sewn. U.S. Pat. No. 4,290,243 issued to Mellin discloses a method of attaching a fabric used in tension structures; this system reinforces the edge of the textile with a hemmed in cable, which is then used as an attachment point for the secondary structure.

The applications listed above demonstrate high load uses for textiles using traditional methods to secure the reinforced the edge of the textile and attach it to a secondary structure. While these current methods of sewn or welded hems to reinforce edges using straps or grommets to transfer loads are generally successful in moderate load applications, they do not perform as well as possible under high loads. Point loading tends focus the load to a limited number of fibers within the panel around the points of attachment such as grommets or straps. This places a greater strain on the fibers directly in line with the grommet or strap making these fibers vulnerable to failure. Additionally, distortion occurs along the border edges as the few fibers aligned with the anchor points bear the greatest percentage of the load. Compounding failures occur across the reinforced edge as the highly tensioned fibers break, causing shock loads to the remaining fibers which cause them to break as well.

Another family of current art uses better load distribution along the edge of the load bearing textile, but still falls short of maximizing the textile strength because the reinforcement method still relies on stitching. U.S. Pat. No. 5,915,449 issued to Schwartz describes a textile blast screen which uses a hemmed in rod to reinforce the top and a hemmed in lead weight to reinforce the bottom; these also serve as attachment points. U.S. Pat. No. 5,746,343 issued to Waltke et al shows a textile bag for liquids supported by having its edges sewn onto a frame. Similarly, U.S. Pat. No. 5,329,719 issued to Holyoak shows a textile containment method for raising and harvesting fish in a body of water having edges that are also sewn onto a frame. While these products have less likelihood of failure at the attachment point and less likelihood of distortion because the loads are better distributed across the panel, the sewn hem is still a potential point of failure. When structural elements are comprised of stitched materials, the panel is subject to stress failure due to shear loading of the stitch. Further still, the process of stitching fabric inherently weakens the textile. Damage to the thread itself, whether by abrasive action or ultraviolet degradation is a concern to manufacturers and consumers of load bearing textile devices. The difficulty is in identifying the progressive degradation and establishing a time period and protocol by which the effective service life of the device can be determined. Additionally, current art disclosures that rely on traditional methods of manufacture are not able to take advantage of labor saving manufactured components and are therefore required to have skilled labor, large facilities and complex machinery to produce a reliable and consistent product. Ultimately these disadvantages increase consumer costs and make the products less desirable. Additionally still, no part of a sewn seam or grommet assembly can be reused nor is it easily repaired in the field.

Current art shows that industry has recognized these problems and has set forth a range of textile clamps and attachment methods which attempt to address the issues above. U.S. Pat. No. 4,686,748 issued to Kaivanto, U.S. Pat. No. 5,692,272 issued to Woods, and U.S. Pat. No. 5,168,605 issued to Bartlett each show a clip for holding fabric. While these clips are all improvements over sewn methods, they still describe single points of attachment that are subject to the same point loading concerns previously noted. In order to distribute high loads evenly across the terminating edge, an excess of these textile clamps would be required. Each clamp would require an anchor into a secondary structure, the quantity necessary would preclude practical use for high load bearing applications.

Modern synthetic fibers are stronger and more durable than the methods current art uses to secure them. Limited to methods described in prior art for securing a textile panel to a secondary structure, industry is not able to take full advantage of the strength of modern fibers in high load applications. The ultimate load carrying capacity and therefore what ultimately limits the use of the textile, has not increased in equal proportion to the increase in strength of the fibers. What is. needed is a method to further increase the load carrying capacity of an article made of high strength synthetic fibers which may be applied/affixed/deployed without the need for specialized skill, facilities or machines.

BRIEF SUMMARY OF THE INVENTION

The invention enables textiles to bear greater loads by increasing the efficiency of load transfer from fibers to a secondary structure. It is removably attached and can be configured and reconfigured to a number of applications having the qualities of lightness, strength, flexibility and durability.

Several objects and advantages of the present invention are:

-   -   (1) To provide a device that maximizes the use of the fiber         strength in textiles, particularly those made from modern         synthetic fibers.     -   (2) To provide a device that serves as an intermediary between a         textile panel and a secondary structure which is incorporated         into the edge of the textile panel and accumulates loads which         can then be transferred to a secondary structure.     -   (3) To provide a device that can be attached to textiles quickly         and easily with simple tools minimizing time and cost of         assembly.     -   (4) To provide a simple device that can be used by non skilled         individuals.     -   (5) To provide a device that is durable and weather resistant.     -   (6) To provide a device that is reusable.     -   (7) To provide a device that enables textiles to be used in new         and innovative ways.     -   (8) To provide a device that is inexpensive to manufacture.     -   (9) To provide a device that is modular, and can be used in         part, as a whole, or in combination with other devices.     -   (10) To provide a device that is lightweight, compact, and easy         to store when not in use.     -   (11) To provide a device that does not require specialized         equipment, fabrication facilities, or methods of assembly such         as sewing machines, welding, adhesives, or other means to secure         it to the textile.     -   (12) To provide a device that is capable of being used with a         wide range of textiles.     -   (13) To provide a device used in high load applications such as         large tents, trucking tarps, heavy lift tarpaulins, etc. For         example, this invention may be used in the hurricane protection         industry where high strength textiles are used as hurricane         shutters and storm panels in any manner of situations where they         serve to cover windows, doors, open areas and even roofs to         block wind, debris impacts or serve as mechanical resistors to         uplift forces or direct wind pressures.

Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

In the drawings, repeat figures have the same number.

FIG. 1 shows a perspective view of the clamp assembly attached to a textile panel

FIG. 2 shows a close-up view of an edge of the sleeve without the rod.

FIG. 3 shows a close-up view of an edge of the sleeve showing how the textile and rod are inserted.

FIG. 4 shows a close-up view of an edge of the clamp assembly fastened.

FIG. 5 shows a cross section of the sleeve.

FIG. 6 shows an exploded profile view of the clamp assembly.

FIG. 7 shows a cross section of the clamp assembly fastened.

DRAWING—REFERENCE NUMERALS

10 Textile 12 Sleeve 14 Rod 16 Hole 18 Fastener

DETAILED DESCRIPTION OF THE INVENTION

This invention describes an intermediary device between a load-bearing textile and a secondary structure which secures the textile in a manner to transfer loads from the textile into an anchor in a fast, cost effective, and strong field assembled clamp that retains much of the strength of the textile and resists load induced deformation from point loading and environmental degradation. The invention replaces the typical and laborious task of gluing and/or sewing reinforcements and/or affixing grommets and/or plates into textiles so that they may carry high loads.

These goals are achieved by the invention by incorporating at the edge of the textile panel a round turn around a length of rod inside a corresponding length of an essentially U-shaped sleeve that forms a compressive clamp around the assembly. To apply the clamp to a textile panel, the edge of the textile is folded once around the rod with sufficient overlap, and then the rod and textile are inserted into the U-shaped sleeve. The two flat sides of the U-shaped sleeve are secured together with readily available hand tools and common mechanical fasteners in sufficient number so that the textile and rod are secured inside the curved part of the U-shaped sleeve. Once secured, the rod and profile of the sleeve engage the textile with an even compressive force.

The profile of the sleeve is such that is serves to hold the rod complimentary within the curve of the U-shaped sleeve. Once secured with fasteners, the diameter of the rounded end of the sleeve is reduced entrapping the textile within the clamp assembly. When load is applied the assembly is drawn tighter. The higher the load gets, the more the rod is forced toward the flat sections of the U-shaped sleeve, which have been fastened together. The rod tends act as a wedge and force the flat sections of the U-shaped sleeve apart, causing the fasteners to resist the outward force. The result is a tightening of the clamp pressure between the flat sections which further compresses the layers of the textile inside the sleeve. The outward force on the flat sections of the U-shaped sleeve further works to keep the fasteners in tight tension and therefore resist unscrewing. By incorporating a rod with a large turning diameter relative to the thickness of the textile and having the textile led around the rod before being clamped between the flat sections of the U-shaped sleeve serves to keep the fiber in alignment with the load direction as the load is transferred into the clamp, this action greatly increases retention of fiber strength. Further, the secured clamp assembly forms a rigid assembly that resists distortion under load by acting as a beam. Further still, as a result of having an entire edge of a textile panel entrapped by the clamp assembly, loads are evenly distributed and therefore does not form point loads. Every fiber within a textile panel is engaged and able to bear loads, thus the device fully utilizes the tensile strength of the textile.

The textile clamp is of such size as to be easily managed. However, the invention could be made larger or smaller, longer or shorter, and multiple assemblies can be placed end-to-end as required by the application.

In manufacturing, it is preferred that the rod is made of pulltruded fiber reinforced plastic or similar material with high resistance to compression. It is further preferred that the U-shaped sleeve is made by extruding a durable plastic such as high density polyethylene, alternate efficient methods of manufacture such as injection molding, or others may be used. It is preferred to use common fasteners such as machine screws and nuts; however any suitable type fastener may be used. It is preferred to use materials resistant to UV and other forms of degradation. While these materials and methods are preferred embodiments of the invention, other materials and methods maybe used to more efficiently produce the parts and the future may yield new materials that may enhance performance. Any of these improved items may be incorporated into the invention without altering the spirit of the invention.

In use, the flat sections of the U-shaped sleeve are held open and the textile and rod are inserted and into the curve of the U. The U-shaped sleeve closes around the rod and the textile and spring tension within the U-shape holds the assembly in place while allowing easy adjustments to the material. Once the desired alignment is achieved, the fasteners are inserted and tightened, locking the clamp assembly together and securing the textile from further movement. The procedure is fast, easy and efficient. The design of the textile clamp enables one worker to install the clamp from one working position making maximum use of labor efforts.

While the invention offers a solution primarily for use in the construction of high load bearing textile panels such as textile-based hurricane panels to protect windows and other openings, the clamp has many other uses in many fields of endeavor where industrial textiles are currently used; such as commercial fishing, fish farming, tent and tarpaulin manufacturing and repair, riparian management, land stabilization, commercial awnings, billboards, signage, sail making, oil and agriculture industry, ocean engineering, and others. Nothing should be construed from this description to limit the scope of this invention. 

1. A load bearing textile clamp comprising: a) An outer compressive sleeve of variable length; b) A rod of variable length; c) Said rod held within said sleeve; d) Said sleeve being shaped complimentary to said rod; e) Said rod and sleeve in conjunction with a textile forming a clamp assembly of variable length; f) Said clamp assembly being secured with fasteners. 